[Lldb-commits] [lldb] r365665 - Options: Reduce code duplication

Pavel Labath via lldb-commits lldb-commits at lists.llvm.org
Wed Jul 10 10:09:47 PDT 2019


Author: labath
Date: Wed Jul 10 10:09:47 2019
New Revision: 365665

URL: http://llvm.org/viewvc/llvm-project?rev=365665&view=rev
Log:
Options: Reduce code duplication

Summary:
While investigating breakages caused by D63110, I noticed we were
building the short options strings in three places. Some of them used a
leading ':' to detect missing arguments, and some didn't. This was the
indirect cause of D63110. Here, I move the common code into a utility
function.

Also, unify the code which appends the sentinel value at the end of the
option vector, and make it harder for users to pass invalid argc-argv
combos to getopt (another component of D63110) by having the
OptionParser::Parse function take a (Mutable)ArrayRef.

This unification has uncovered that we don't handle missing arguments
while building aliases, However, it's not possible to write an effective
test for this, as right now it is not possible to return an error out of
the alias parsing code (which means we are printing the generic
"failure" message even after this patch).

Reviewers: mgorny, aprantl

Reviewed By: mgorny

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D63770

Modified:
    lldb/trunk/include/lldb/Host/OptionParser.h
    lldb/trunk/source/Host/common/OptionParser.cpp
    lldb/trunk/source/Interpreter/CommandAlias.cpp
    lldb/trunk/source/Interpreter/Options.cpp

Modified: lldb/trunk/include/lldb/Host/OptionParser.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/include/lldb/Host/OptionParser.h?rev=365665&r1=365664&r2=365665&view=diff
==============================================================================
--- lldb/trunk/include/lldb/Host/OptionParser.h (original)
+++ lldb/trunk/include/lldb/Host/OptionParser.h Wed Jul 10 10:09:47 2019
@@ -13,6 +13,7 @@
 #include <string>
 
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/ArrayRef.h"
 
 struct option;
 
@@ -37,8 +38,11 @@ public:
 
   static void EnableError(bool error);
 
-  static int Parse(int argc, char *const argv[], llvm::StringRef optstring,
-                   const Option *longopts, int *longindex);
+  /// Argv must be an argument vector "as passed to main", i.e. terminated with
+  /// a nullptr.
+  static int Parse(llvm::MutableArrayRef<char *> argv,
+                   llvm::StringRef optstring, const Option *longopts,
+                   int *longindex);
 
   static char *GetOptionArgument();
   static int GetOptionIndex();

Modified: lldb/trunk/source/Host/common/OptionParser.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Host/common/OptionParser.cpp?rev=365665&r1=365664&r2=365665&view=diff
==============================================================================
--- lldb/trunk/source/Host/common/OptionParser.cpp (original)
+++ lldb/trunk/source/Host/common/OptionParser.cpp Wed Jul 10 10:09:47 2019
@@ -27,8 +27,9 @@ void OptionParser::Prepare(std::unique_l
 
 void OptionParser::EnableError(bool error) { opterr = error ? 1 : 0; }
 
-int OptionParser::Parse(int argc, char *const argv[], llvm::StringRef optstring,
-                        const Option *longopts, int *longindex) {
+int OptionParser::Parse(llvm::MutableArrayRef<char *> argv,
+                        llvm::StringRef optstring, const Option *longopts,
+                        int *longindex) {
   std::vector<option> opts;
   while (longopts->definition != nullptr) {
     option opt;
@@ -41,7 +42,8 @@ int OptionParser::Parse(int argc, char *
   }
   opts.push_back(option());
   std::string opt_cstr = optstring;
-  return getopt_long_only(argc, argv, opt_cstr.c_str(), &opts[0], longindex);
+  return getopt_long_only(argv.size() - 1, argv.data(), opt_cstr.c_str(),
+                          &opts[0], longindex);
 }
 
 char *OptionParser::GetOptionArgument() { return optarg; }

Modified: lldb/trunk/source/Interpreter/CommandAlias.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Interpreter/CommandAlias.cpp?rev=365665&r1=365664&r2=365665&view=diff
==============================================================================
--- lldb/trunk/source/Interpreter/CommandAlias.cpp (original)
+++ lldb/trunk/source/Interpreter/CommandAlias.cpp Wed Jul 10 10:09:47 2019
@@ -30,6 +30,8 @@ static bool ProcessAliasOptionsArgs(lldb
 
   Args args(options_args);
   std::string options_string(options_args);
+  // TODO: Find a way to propagate errors in this CommandReturnObject up the
+  // stack.
   CommandReturnObject result;
   // Check to see if the command being aliased can take any command options.
   Options *options = cmd_obj_sp->GetOptions();

Modified: lldb/trunk/source/Interpreter/Options.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Interpreter/Options.cpp?rev=365665&r1=365664&r2=365665&view=diff
==============================================================================
--- lldb/trunk/source/Interpreter/Options.cpp (original)
+++ lldb/trunk/source/Interpreter/Options.cpp Wed Jul 10 10:09:47 2019
@@ -930,6 +930,7 @@ static std::vector<char *> GetArgvForPar
   result.push_back(const_cast<char *>("<FAKE-ARG0>"));
   for (const Args::ArgEntry &entry : args)
     result.push_back(const_cast<char *>(entry.c_str()));
+  result.push_back(nullptr);
   return result;
 }
 
@@ -972,19 +973,15 @@ static size_t FindArgumentIndexForOption
   return size_t(-1);
 }
 
-llvm::Expected<Args> Options::ParseAlias(const Args &args,
-                                         OptionArgVector *option_arg_vector,
-                                         std::string &input_line) {
-  StreamString sstr;
-  int i;
-  Option *long_options = GetLongOptions();
+static std::string BuildShortOptions(const Option *long_options) {
+  std::string storage;
+  llvm::raw_string_ostream sstr(storage);
 
-  if (long_options == nullptr) {
-    return llvm::make_error<llvm::StringError>("Invalid long options",
-                                               llvm::inconvertibleErrorCode());
-  }
+  // Leading : tells getopt to return a : for a missing option argument AND to
+  // suppress error messages.
+  sstr << ":";
 
-  for (i = 0; long_options[i].definition != nullptr; ++i) {
+  for (size_t i = 0; long_options[i].definition != nullptr; ++i) {
     if (long_options[i].flag == nullptr) {
       sstr << (char)long_options[i].val;
       switch (long_options[i].definition->option_has_arg) {
@@ -1000,6 +997,20 @@ llvm::Expected<Args> Options::ParseAlias
       }
     }
   }
+  return std::move(sstr.str());
+}
+
+llvm::Expected<Args> Options::ParseAlias(const Args &args,
+                                         OptionArgVector *option_arg_vector,
+                                         std::string &input_line) {
+  Option *long_options = GetLongOptions();
+
+  if (long_options == nullptr) {
+    return llvm::make_error<llvm::StringError>("Invalid long options",
+                                               llvm::inconvertibleErrorCode());
+  }
+
+  std::string short_options = BuildShortOptions(long_options);
 
   Args args_copy = args;
   std::vector<char *> argv = GetArgvForParsing(args);
@@ -1009,8 +1020,13 @@ llvm::Expected<Args> Options::ParseAlias
   int val;
   while (true) {
     int long_options_index = -1;
-    val = OptionParser::Parse(argv.size(), &*argv.begin(), sstr.GetString(),
-                              long_options, &long_options_index);
+    val = OptionParser::Parse(argv, short_options, long_options,
+                              &long_options_index);
+
+    if (val == ':') {
+      return llvm::createStringError(llvm::inconvertibleErrorCode(),
+                                     "last option requires an argument");
+    }
 
     if (val == -1)
       break;
@@ -1116,33 +1132,13 @@ llvm::Expected<Args> Options::ParseAlias
 OptionElementVector Options::ParseForCompletion(const Args &args,
                                                 uint32_t cursor_index) {
   OptionElementVector option_element_vector;
-  StreamString sstr;
   Option *long_options = GetLongOptions();
   option_element_vector.clear();
 
   if (long_options == nullptr)
     return option_element_vector;
 
-  // Leading : tells getopt to return a : for a missing option argument AND to
-  // suppress error messages.
-
-  sstr << ":";
-  for (int i = 0; long_options[i].definition != nullptr; ++i) {
-    if (long_options[i].flag == nullptr) {
-      sstr << (char)long_options[i].val;
-      switch (long_options[i].definition->option_has_arg) {
-      default:
-      case OptionParser::eNoArgument:
-        break;
-      case OptionParser::eRequiredArgument:
-        sstr << ":";
-        break;
-      case OptionParser::eOptionalArgument:
-        sstr << "::";
-        break;
-      }
-    }
-  }
+  std::string short_options = BuildShortOptions(long_options);
 
   std::unique_lock<std::mutex> lock;
   OptionParser::Prepare(lock);
@@ -1153,10 +1149,6 @@ OptionElementVector Options::ParseForCom
 
   std::vector<char *> dummy_vec = GetArgvForParsing(args);
 
-  // I stick an element on the end of the input, because if the last element
-  // is option that requires an argument, getopt_long_only will freak out.
-  dummy_vec.push_back(const_cast<char *>("<FAKE-VALUE>"));
-
   bool failed_once = false;
   uint32_t dash_dash_pos = -1;
 
@@ -1164,8 +1156,8 @@ OptionElementVector Options::ParseForCom
     bool missing_argument = false;
     int long_options_index = -1;
 
-    val = OptionParser::Parse(dummy_vec.size(), &dummy_vec[0], sstr.GetString(),
-                              long_options, &long_options_index);
+    val = OptionParser::Parse(dummy_vec, short_options, long_options,
+                              &long_options_index);
 
     if (val == -1) {
       // When we're completing a "--" which is the last option on line,
@@ -1328,7 +1320,6 @@ llvm::Expected<Args> Options::Parse(cons
                                     ExecutionContext *execution_context,
                                     lldb::PlatformSP platform_sp,
                                     bool require_validation) {
-  StreamString sstr;
   Status error;
   Option *long_options = GetLongOptions();
   if (long_options == nullptr) {
@@ -1336,38 +1327,15 @@ llvm::Expected<Args> Options::Parse(cons
                                                llvm::inconvertibleErrorCode());
   }
 
-  // Leading : tells getopt to return a : for a missing option argument AND to
-  // suppress error messages.
-  sstr << ":";
-  for (int i = 0; long_options[i].definition != nullptr; ++i) {
-    if (long_options[i].flag == nullptr) {
-      if (isprint8(long_options[i].val)) {
-        sstr << (char)long_options[i].val;
-        switch (long_options[i].definition->option_has_arg) {
-        default:
-        case OptionParser::eNoArgument:
-          break;
-        case OptionParser::eRequiredArgument:
-          sstr << ':';
-          break;
-        case OptionParser::eOptionalArgument:
-          sstr << "::";
-          break;
-        }
-      }
-    }
-  }
+  std::string short_options = BuildShortOptions(long_options);
   std::vector<char *> argv = GetArgvForParsing(args);
-  // If the last option requires an argument but doesn't have one,
-  // some implementations of getopt_long will still try to read it.
-  argv.push_back(nullptr);
   std::unique_lock<std::mutex> lock;
   OptionParser::Prepare(lock);
   int val;
   while (true) {
     int long_options_index = -1;
-    val = OptionParser::Parse(argv.size() - 1, &*argv.begin(), sstr.GetString(),
-                              long_options, &long_options_index);
+    val = OptionParser::Parse(argv, short_options, long_options,
+                              &long_options_index);
 
     if (val == ':') {
       error.SetErrorStringWithFormat("last option requires an argument");




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